A Greek slang word refering to people who have the characteristics of a group which is at the same time alternative yet mainstream.
Fasaios doesn't belong to fringe groups, instead he is part of a group which started as an alternative underground sub-culture yet it was adopted by so many people that it became mainstream.
Currently, Fasaios has a hippie or boho-like fashion sense and the word is mostly used to refer to people of said style, but to fully be a fasaios one must also adopt the social attitudes it entails.
Fasaios listen to the same music (entehno), goes to same places for vacation and has the same short-term hobbies as his subgroup and only has a social life inside said subgroup. If one person has the fasaios style but also has a social life outside of said group then he cannot be fully called a fasaios.
-Kostas will go to Thanasis Papakonstantinou's concert tommorow.
-Ah he's such a fasaios, I heard he will go camping in Samothrace this summer too!